JP5144814B2 - Copper alloy material for electrical and electronic parts - Google Patents

Description

  The present invention relates to a copper alloy material applied to electrical and electronic parts such as lead frames, connectors, terminal materials, relays, switches, and sockets, and a method for manufacturing the same.

Tin-plated material with tin plating on a metal substrate such as copper or copper alloy is inexpensive, but has low contact resistance, corrosion resistance and solderability of the plating layer in addition to the excellent conductivity and strength of the substrate Therefore, it is widely used for various terminals and connectors as a high-performance contact conductor material.
Also, in some applications of tin plating materials, it is used for a long time in a high temperature environment, in which case the tin of the tin plating layer disappears due to thermal diffusion into the substrate, and the plating function deteriorates. It becomes. Therefore, underplating such as nickel or cobalt is applied to the lower layer of the tin plating layer to reduce thermal diffusion of tin. The nickel or cobalt base plating layer between the tin plating layer and the substrate material functions as a barrier layer for tin diffusion.
Thus, two types of tin plating materials have been developed for the presence or absence of base plating depending on the use environment.

The following changes are mentioned in the situation where the tin plating material in recent years is used.
First, as the functionality of automobiles, electric machines, and electronic devices has been improved, the number of connectors has been increased, so that miniaturization of terminals and contact parts has progressed. For example, a movement to downsize a terminal having a tab width of about 1.0 mm to 0.64 mm is progressing.
Second, in order to reduce mineral resources and reduce the weight of parts, the substrate material is becoming thinner, and in order to maintain the spring contact pressure, a substrate material having higher strength than before is required. .
Thirdly, the use environment is becoming hot. For example, to reduce the amount of carbon dioxide generated in automobile parts, electronic devices such as ECUs for engine control, which were conventionally installed on doors, are installed in the engine room and in the vicinity of the engine to reduce the weight of the vehicle body. However, the movement to shorten the wire harness between the electronic device and the engine is progressing.

On the other hand, with the above change, the following problems have arisen in the plating material.
Along with the miniaturization of the terminals, the bending radius of the bending process applied to the contact part and the spring part becomes smaller, and the plating material is subjected to a more severe bending process than before. Therefore, there is a problem that cracks occur in the plating portion of the plating material or in the plating portion and the base material.
As the strength of plating materials increases, the bending workability of plating materials generally has a trade-off relationship with strength, which causes the problem that cracks occur in the plating portion of the plating material or in the plating portion and the substrate. Yes.
In order to prevent the tin plating layer from disappearing due to thermal diffusion as the usage environment becomes higher, it is necessary to thicken the underlying plating such as nickel or cobalt as the barrier layer. Since it is hard and poor in ductility, there is a problem that cracks are generated based on this barrier plating layer when bending is performed.
If a crack occurs in the bent part applied to the contact part or spring part, the contact pressure of the contact part decreases, the contact resistance of the contact part increases, the electrical connection is insulated, and the function as a connector is achieved. It will be lost.

The following techniques have been proposed as conventional methods for solving the above problems.
With respect to a tin plating material that does not include an underlayer such as nickel or cobalt, Patent Document 1 prevents the formability from being deteriorated by controlling the thickness of the Cu—Sn compound layer.
Regarding the tin plating material including an underlayer such as nickel or cobalt, in Patent Documents 2 and 3, the thickness of the nickel undercoat layer is controlled, and in Patent Document 4, the nickel undercoat layer and the Cu—Sn compound layer are used. By controlling the thickness, bending workability is prevented from deteriorating.
However, with these methods, it has become difficult to prevent the occurrence of cracks with a small bending radius of a state-of-the-art small terminal. In addition, since the control of the thickness of the plating layer may impair the function as an important plating, it may not be a radical solution.

JP 2006-183068 A JP 2003-147579 A JP 2003-293187 A JP 2004-068026 A

  Even when bent under severe bending conditions with a small bending radius, or when bent using a high-strength base material, cracks do not occur in the plated part of the plating material or in the plated part and the metal base material. There is a need for tin plating materials. In particular, the method of suppressing cracks in the plating portion and the base material by controlling the thickness of the plating leads to a decrease in the plating function such as a decrease in heat resistance. Therefore, other methods are required.

The present inventors have studied tin-plated materials suitable for electric / electronic component applications, and there is a correlation between the area ratio of the cube orientation of the copper or copper alloy base material and the frequency of occurrence of cracks after bending of the tin-plated material. As a result, the present invention has been made through repeated studies.
In addition to that, the present inventors have found an alloy composition of a base material satisfying the strength and conductivity required for a tin plating material while increasing the cube orientation area of the base material, leading to the invention.
Furthermore, the inventors have invented an additive element that has the function of improving the stress relaxation resistance without impairing the conductivity and bending workability of the base material.

That is, the present invention provides the following solutions.
(1) On a base made of a copper alloy,
At least an alloy layer containing copper and tin, a copper alloying material for electric and electronic parts which is formed by heating and melting treatment and plating treatment,
The area ratio of the region within 20 ° from the cube orientation {0 0 1} <1 0 0> in the EBSD method crystal orientation measurement of the substrate is 5% or more,
The substrate contains at least one of nickel or cobalt in a total amount of 0.4 to 5.0 mass%, contains silicon in an amount of 0.1 to 1.5 mass%, and the balance is composed of copper and inevitable impurities, The substrate is obtained by removing a work-affected layer on the surface layer,
Adjacent on the substrate, which undercoat plating layer is provided containing at least one of nickel or cobalt,
The copper alloy material was bent at 90 ° W with an inner radius of 0.15 mm, and the contact resistance at the apex of the bent portion after heating in the atmosphere at a temperature of 140 ° C. for 120 hours had a load of 490 mN via an Ag probe. A copper alloy material for electrical and electronic parts, characterized by being 10 mΩ or less under the conditions of
(2) On a base made of a copper alloy,
At least an alloy layer containing copper and tin, a copper alloy material for electric and electronic parts which is formed by heating and melting treatment and plating treatment,
The area ratio of the region within 20 ° from the cube orientation {0 0 1} <1 0 0> in the EBSD method crystal orientation measurement of the substrate is 5% or more,
The base body contains at least one of nickel and cobalt in a total amount of 0.4 to 5.0 mass%, silicon in a range of 0.1 to 1.5 mass%, tin, zinc, silver, manganese, boron, phosphorus, magnesium. , Chromium, iron, titanium, zirconium and hafnium at least one selected from the group consisting of 0.005 to 2.0 mass% in total, with the balance being composed of copper and unavoidable impurities, the substrate being a surface layer Removing the damaged layer of
Adjacent on the substrate, which undercoat plating layer is provided containing at least one of nickel or cobalt,
The copper alloy material was bent at 90 ° W with an inner radius of 0.15 mm, and the contact resistance at the apex of the bent portion after heating in the atmosphere at a temperature of 140 ° C. for 120 hours had a load of 490 mN via an Ag probe. A copper alloy material for electrical and electronic parts, characterized by being 10 mΩ or less under the conditions of
(3) The copper alloy material for electrical and electronic parts according to (1) or (2), wherein an outermost layer made of tin or a tin alloy is provided on the alloy layer.
(4) The copper alloy for electrical and electronic parts according to (1) or (2), wherein an intermediate layer made of copper or a copper alloy is provided between the base plating layer and the alloy layer. material.
(5) An intermediate layer made of copper or a copper alloy is provided between the base plating layer and the alloy layer, and an outermost layer made of tin or a tin alloy is provided on the alloy layer. The copper alloy material for electrical and electronic parts according to (1) or (2), characterized in that it is characterized.
(6) An electrical / electronic component formed by processing the copper alloy material according to any one of (1) to (5).
(7) From a copper alloy having a composition containing at least one of nickel or cobalt in a total amount of 0.4 to 5.0 mass%, containing silicon in a range of 0.1 to 1.5 mass%, and the balance consisting of copper and inevitable impurities. A base obtained by hot rolling an ingot that has been subjected to homogenization heat treatment at 850 to 1020 ° C., water-cooling or air-cooling to 800 ° C. or less, and performing high-temperature rolling at a total processing rate of 40% or more at 500 to 800 ° C. above,
A base plating layer containing at least one of nickel or cobalt, a copper plating layer made of copper or a copper alloy, and a tin plating layer made of tin or a tin alloy are formed in this order. A method for producing a copper alloy material for electrical and electronic parts, wherein the tin plating layer is melted by a heat melting treatment for 120 seconds to form an alloy layer composed of constituent elements of the copper plating layer and constituent elements of the tin plating layer. There,
The area ratio of the region within 20 ° from the cube orientation {0 0 1} <1 0 0> in the EBSD method crystal orientation measurement of the substrate after the heat-melting treatment is 5% or more, A method for producing a copper alloy material for electronic parts.
(8) Containing at least one of nickel or cobalt in a total amount of 0.4 to 5.0 mass%, containing silicon in a range of 0.1 to 1.5 mass%, tin, zinc, silver, manganese, boron, phosphorus, magnesium, Containing at least one selected from the group consisting of chromium, iron, titanium, zirconium and hafnium in a total amount of 0.005 to 2.0 mass%, the balance being a copper alloy having a composition consisting of copper and inevitable impurities, and homogenizing On the substrate obtained by hot-rolling the heat-treated ingot at 850 to 1020 ° C., water-cooling or air-cooling to 800 ° C. or less and performing high-temperature rolling at a total processing rate of 40% or more at 500 to 800 ° C.,
A base plating layer containing at least one of nickel or cobalt, a copper plating layer made of copper or a copper alloy, and a tin plating layer made of tin or a tin alloy are formed in this order. A method for producing a copper alloy material for electrical and electronic parts, wherein the tin plating layer is melted by a heat melting treatment for 120 seconds to form an alloy layer composed of constituent elements of the copper plating layer and constituent elements of the tin plating layer. There,
The area ratio of the region within 20 ° from the cube orientation {0 0 1} <1 0 0> in the EBSD method crystal orientation measurement of the substrate after the heat-melting treatment is 5% or more, A method for producing a copper alloy material for electronic parts.
Here, the cube orientation is an orientation in which the <0 0 1> direction of the crystal is parallel to the rolling direction, the rolling surface normal, and the width direction.

  The copper alloy material for electric and electronic parts of the present invention is excellent in bending workability and does not cause cracks in tin or tin plating (outermost layer) and the base material. Therefore, it is useful as a contact material of a connector. Further, according to the method for producing a copper alloy material for electric and electronic parts of the present invention, a copper alloy material for electric and electronic parts used for the connector having the above excellent physical properties can be obtained.

FIG. 1A is an explanatory diagram of the deviation angle. FIG. 1B is an explanatory diagram of the coordinate system in FIG. It is explanatory drawing of the test method of a stress relaxation resistance characteristic.

  A preferred embodiment of the copper alloy material of the present invention will be described in detail. Here, the “copper alloy material” means a material obtained by processing a copper alloy material into a predetermined shape (for example, a plate, a strip, a foil, a bar, a wire, or the like). In addition, a board | plate material and a strip are demonstrated as embodiment.

In order to clarify the cause of the occurrence of cracks during bending of the tin plating material, the present inventors investigated in detail the metal structure of the tin plating material after bending deformation. As a result, it was observed that the base material was not uniformly deformed, but non-uniform deformation progressed, in which the deformation was concentrated only in a region having a specific crystal orientation. It was found that due to the non-uniform deformation, wrinkles with a depth of several microns and fine cracks were generated on the surface of the base material after bending, resulting in cracks in the tin plating.
In the case of a plating structure in which a plurality of phases are stacked as in the present invention, the base layer such as Ni or Co and the diffusion layer such as Cu-Sn compound have higher strength than the surrounding Sn and the base material, and these The difference in deformation behavior between layers is a problem. As a result, the base layer and the diffusion layer are poor in ductility, and breakage occurs before the surroundings, and the entire plating layer is cracked starting from the breakage. Therefore, plating cracking in multilayer plating is an essential problem. In order to solve this problem, the present invention takes a technique of changing the deformation state by adjusting the surface of the base material to be plated so as to have a specific crystal orientation.
As specified in the present invention, when the cube orientation area ratio of the base material is set to a predetermined size, uneven deformation is suppressed, wrinkles generated on the surface of the base material are reduced, and cracking of the tin plating is suppressed. I understood that.
Further, the present inventors have found that the nickel and copper underlayers are also oriented in the cube orientation, and the uneven deformation body is less likely to develop in the plating itself.

  The cube azimuth area ratio is the ratio of the area of the cube azimuth to the measured area of the sample measured by the EBSD method (electron backscatter diffraction image method) or the like. The above effect is obtained when the cube area ratio is 5% or more. Preferably, it is 7% or more, more preferably 10% or more. The upper limit is not particularly limited, but is preferably 50% or less. If the cube orientation area ratio is too large, the work hardening amount of the material may decrease, and the contact pressure of the spring contact may decrease.

  The crystal orientation display method in the present specification takes a rectangular coordinate system in which the rolling direction (RD) of the material is the X axis, the sheet width direction (TD) is the Y axis, and the rolling normal direction (ND) is the Z axis. Using the index (h k l) of the crystal plane each region in which is perpendicular to the Z axis (parallel to the rolling surface) and the index [u v w] of the crystal direction parallel to the X axis, (h k l) Shown in the form [u v w]. In addition, as for (1 3 2) [6 -4 3] and (2 3 1) [3 -4 6], etc. It uses {h k l} <u v w> using the parenthesis symbol to represent.

  The EBSD method was used for the analysis of the crystal orientation in the present invention. The EBSD method (electron backscatter diffraction image method) is an abbreviation of Electron Back Scatter Diffraction, and the reflected electron Kikuchi line diffraction image (SEM) generated when a sample is irradiated with an electron beam in a scanning electron microscope (SEM). This is crystal orientation analysis technology using the Kikuchi pattern. Here, a 500 μm square sample area containing 200 or more crystal grains was scanned in 0.5 μm steps, and the orientation was analyzed.

  The deviation angle is obtained by calculating the rotation angle around a common rotation axis. FIG. 1A and FIG. 1B are explanatory diagrams of the shift angle. Example 1 in FIG. 1A is an example rotated with the (1 0 0) direction as a rotation axis, Example 2 is an example rotated with the (1 1 0) direction as a rotation axis, and Example 3 is (1 1 1) Each example rotated with the direction as the axis of rotation. For example, with respect to the cube orientation (0 0 1) [1 0 0], (−1 1 5) [5 0 1] is rotated by 15 ° with the (1 1 0) direction as the rotation axis, (−1 1 10 ) [9 -1 1] has a relationship of 10 ° rotation with the (1 1 1) direction as the axis of rotation. This angle was defined as a deviation angle. A common rotation axis that can be expressed at the smallest angle is adopted. The calculation method of the area ratio itself is a normal method. The deviation angle is calculated for all measurement points, the first decimal place is an effective number, and the deviation angle from the cube orientation is within 20 °. The area of the crystal grains is divided by the total measurement area to obtain the area ratio. FIG. 1B shows the coordinate system in FIG. In addition, the rotation angle in FIG. 1 (A) is rounded off and displayed as an integer.

  The information obtained in the azimuth analysis by EBSD includes azimuth information up to a depth of several tens of nanometers at which the electron beam penetrates into the sample. It was described as an area ratio. The measurement was performed from the plate surface.

  In the EBSD measurement, in order to obtain a clear Kikuchi line diffraction image (Kikuchi pattern), the surface of the substrate was mirror-polished using a colloidal silica abrasive after mechanical polishing, and then the measurement was performed.

Copper or copper alloy is used as the base material metal of the connector terminal of the present invention. These base copper alloys can be appropriately selected from conventionally known copper alloys. Preferred embodiments for improving the physical properties will be described below.
Copper alloys such as copper, phosphor bronze, brass, western white, beryllium copper, and Corson alloy (Cu—Ni—Si) having electrical conductivity, mechanical strength and heat resistance required for the connector are preferable. In particular, when it is desired to increase the area ratio of the cube orientation, a pure copper material, beryllium copper, or a Corson alloy is preferable. Furthermore, in order to achieve both high strength and high conductivity as required for the most advanced small terminal materials, Cu—Ni—Si and Cu—Ni—Co—Si copper alloys are preferable.

  By controlling the respective addition amounts of nickel (Ni), cobalt (Co), and silicon (Si), which are the first additive element group added to copper (Cu), Ni—Si, Co—Si, Ni The strength of the copper alloy can be improved by precipitating a Co—Si compound. The total amount of one or two of nickel and cobalt is 0.4 to 5.0 mass%, preferably 0.6 to 4.5 mass%, more preferably 0.8 to 4.0 mass%. The Si content is 0.1 to 1.5 mass%, preferably 0.2 to 1.2 mass%. The total amount of these elements added is 0.5 to 5.1 mass%. If this amount is too large, the electrical conductivity is lowered, and if it is too small, the strength may be insufficient.

Next, the effect of an additive element that improves characteristics (secondary characteristics) such as stress relaxation resistance will be described. Preferred additive elements include tin (Sn), zinc (Zn), silver (Ag), manganese (Mn), boron (B), phosphorus (P), magnesium (Mg), chromium (Cr), and iron (Fe). , Titanium (Ti), zirconium (Zr) and hafnium (Hf). In order to fully utilize the additive effect and not lower the electrical conductivity, the total amount needs to be 0.005 to 2.0 mass%, preferably 0.01 to 0.9 mass%, more preferably, It is 0.03-0.8 mass%. If the total amount of these additive elements exceeds 2 mass%, an adverse effect of lowering the electrical conductivity may occur, which is not preferable. In addition, when these additional elements are less than 0.005 mass% in total amount, the effect which added these elements is hardly exhibited.
The effect of adding each element is shown below. By adding Sn, Zn, and Mg to the Cu—Ni—Si, Cu—Ni—Co—Si, and Cu—Co—Si copper alloys, the stress relaxation resistance is improved. The stress relaxation resistance is further improved by a synergistic effect when added together than when they are added. In addition, there is an effect of remarkably improving solder embrittlement. Moreover, when Ag is contained, there exists an effect which intensity | strength improves by the solid solution effect.
Further, Mn, B, P, Cr, Fe, Ti, Zr, and Hf have effects such as improvement in strength due to refinement of crystal grains.

Next, a method for controlling the area ratio of the cube orientation of the crystal orientation of the base material will be described. Here, a description will be given using a precipitation-type copper alloy plate material (strip material) as an example.
In general, a precipitation-type copper alloy is obtained by thinning a homogenized heat-treated ingot at each step of hot and cold, and performing an intermediate solution heat treatment in a temperature range of 700 to 1020 ° C. to re-solidify solute atoms. Later, it is manufactured to satisfy the required strength by aging precipitation heat treatment and finish cold rolling. These production conditions vary slightly depending on the copper alloy composition, but the ingot homogenization heat treatment condition is preferably 800 to 1020 ° C. for 3 minutes to 10 hours. The hot rolling of the ingot is preferably performed at 500 to 1000 ° C, and the cold rolling is preferably performed at room temperature to 200 ° C. The processing rate of cold rolling is preferably 80 to 99.9%. The conditions for the aging precipitation heat treatment and the finish cold rolling are adjusted according to characteristics such as desired strength and conductivity. As a specific example, the aging precipitation heat treatment is preferably performed at 350 to 650 ° C., more preferably 400 to 600 ° C., preferably 1 minute to 10 hours, more preferably 10 minutes to 6 hours. The texture of the copper alloy is roughly determined by recrystallization that occurs during the intermediate solution heat treatment in this series of steps, and finally determined by the orientation rotation that occurs during finish rolling.

In order to increase the cube orientation area ratio in the intermediate solution heat treatment, it is effective to set the temperature so as to sufficiently dissolve the solute element. Further, in order to increase the cube orientation area ratio, hot rolling is preferably performed at a processing rate of 40% or less, more preferably 3% to 20% per pass. Temperature during hot rolling, 8 50 ℃ ~1020 ℃, good Mashiku is a 900 ° C. to 1000 ° C.. After breaking the cast structure by the dynamic and static recrystallization in hot rolling process, once it cooled with water or air-cooled to 800 ° C. or less, 5 00 ° C. to 800 ° C., further preferably at a temperature of 550 ° C. to 750 ° C., By performing high temperature rolling with a total processing rate of 40% or more (preferably 90% or less), the cube orientation area ratio can be controlled within the range defined in the present invention.
In the present invention, in the temperature range between the lower limit value of the hot rolling temperature and the upper limit value of the high temperature rolling temperature, preferably in the intermediate temperature range of 800 ° C to 850 ° C, more preferably 750 ° C to 900 ° C, rolling is performed. It is preferable to perform water cooling or air cooling without performing the above. The reason is shown below. This temperature zone is the temperature zone where precipitation of solute elements is fastest. Note that the temperature higher than the intermediate temperature zone is a temperature at which the solute element is substantially dissolved, and the temperature lower than the intermediate temperature zone is slow in the movement of atoms, so that precipitation is slight. And when this is preferably rolled at an intermediate temperature range of 800 ° C. to 850 ° C., more preferably 750 ° C. to 900 ° C., precipitation is further accelerated due to an increase in lattice defects, and the size is around several microns. Coarse precipitates are generated. Next, in high-temperature rolling at 500 ° C. to 800 ° C. and subsequent cold rolling, strain concentrates around the coarse precipitate particles having a size of about several microns. As a result, in the intermediate solution heat treatment, recrystallized grains having random orientation may be generated from a high strain region around the particle, and a desired cube orientation area ratio may not be obtained. That is, in order to achieve the cube orientation area ratio defined in the present invention, it is important to control coarsely precipitated particles. For this purpose, it is preferable not to perform rolling at the intermediate temperature. Therefore, for the above reason, it is more preferable to change the intermediate temperature by water cooling rather than air cooling.

In addition, when plating the base material of the present invention, it is possible to perform adhesion by performing a conventional pretreatment means, for example, cathodic electrolytic degreasing in an aqueous solution of sodium hydroxide 60 g / liter and dipping in dilute sulfuric acid. It is possible to form an excellent plating film. In order to improve adhesion and bending workability, the effect of controlling the crystal orientation of the base material can be further improved by removing the work-affected layer formed on the surface of the base material before plating. It may be obtained sufficiently.
In the present invention, a work-affected layer is a layer formed under the influence of heat, working force, ambient atmosphere, properties of a new metal surface, etc. generated during a buffing process or temper rolling (machining). It exhibits a finer structure than the crystal structure inside the substrate. The work-affected layer is composed of a Bailby layer (upper layer) and a plastically deformed layer (lower layer), the Bailby layer is composed of an extremely fine crystalline texture or an amorphous structure, and the plastically deformed layer is non-uniform with many strains. It consists of a crystallographic texture, and the size of the crystal grains is approximately halfway between the crystal grains of the Bailby layer and the crystal grains inside the metal substrate. In the present invention, these work-affected layers are removed. Whether or not the work-affected layer is completely removed can be determined in consideration of the surface state of the metal substrate after the work-affected layer is removed. preferable.
The work-affected layer is a thermally unstable structure, and changes into a thermally stable atomic arrangement by atomic diffusion due to heat during the heat-melting process, and the work-affected layer decreases. Therefore, in the case of plating that performs the heat-melting treatment as in the present invention, there is little advantage of removing the work-affected layer before plating, and it is considered uncommon to remove the work-affected layer before plating. . Incidentally, in the case of Ni plating, Cu plating, Ag plating, etc., it is common not to perform the heat melting treatment after plating.

For removal of the work-affected layer of the metal substrate, sulfuric acid, nitric acid, hydrochloric acid, hydrogen peroxide, hydrofluoric acid and other acid single-solution solutions or mixed aqueous solutions, electrolysis in an electrolytic solution, sputtering method, Conventional methods such as an etching method can be applied.
The thickness of the work-affected layer is determined by the material, casting and rolling conditions, and buffing conditions. Therefore, if the thickness of the work-affected layer is examined in advance for each material and manufacturing method, the work-affected layer is a metal It can be removed without observing the exposed surface of the substrate. For example, the thickness of the oxide layer and the adsorbate layer on the surface of the cast and buffed plate is about 0.01 to 0.1 μm, and the thickness of the work-affected layer is about 0.3 to 0.4 μm, Accordingly, the work-affected layer is removed by removing the surface layer of the metal substrate by about 0.4 μm, preferably about 0.5 μm, before plating.

  Incidentally, pickling treatment is known as a technique for treating the surface of a metal substrate with an acid. The pickling treatment is intended to remove the oxide film on the surface of the metal substrate in order to improve adhesion. It is immersed in dilute sulfuric acid for several seconds. Therefore, the surface layer thickness dissolved and removed is only tens of nanometers at most, and the work-affected layer is hardly removed.

The electrotin plating may be performed, for example, using a tin sulfate bath at a plating temperature of 30 ° C. or less and a current density of 5 A / dm ² . However, the conditions are not limited to this, and can be set as appropriate.
There is no restriction | limiting in particular about the component composition and kind of tin plating formed in this invention. Examples of tin plating that can be used in the present invention include tin, tin-silver, tin-nickel, tin-copper, tin-lead, and tin-antimony. The thickness of the tin plating layer is preferably 0.1 μm or more, more preferably 0.5 to 5 μm.
Furthermore, in the present invention, as a pretreatment for plating, a base plating such as nickel or cobalt can be provided on the base material by a conventional method, for example, with a coating thickness of about 0.2 to 5 μm. Absent.
Furthermore, in this invention, it is preferable to form the copper plating layer which consists of copper or a copper alloy as an intermediate | middle layer of the lower layer of a tin plating layer.
In the present invention, an alloy layer containing at least copper and tin is formed on a base made of a copper alloy. The copper plating layer made of copper or a copper alloy is formed by forming a tin plating layer made of tin or a tin alloy thereon, preferably with a thickness of 0.2 to 10 μm, more preferably 0.5 to 5 μm. Then, the tin plating layer can be melted by a heat melting process to form an alloy layer composed of the constituent elements of the copper plating layer and the constituent elements of the tin plating layer. The heat-melting process in this case (reflow treatment), at 2 50 to 800 ° C., the time is carried out 0.1 to 120 seconds.

  EXAMPLES Hereinafter, although this invention is demonstrated further in detail based on an Example, this invention is not limited to them.

Example 1
[Manufacture of substrate materials]
It mix | blends so that it may contain the 1st addition element in the ratio shown in Table 1, the remainder consists of an alloy which consists of Cu and an unavoidable impurity with a high frequency melting furnace, this is 0.1-100 degree-C / sec cooling rate. An ingot was obtained by casting. This was subjected to hot rolling at a temperature of 850 ° C. to 1020 ° C. after a homogenization heat treatment at a temperature of 900 to 1020 ° C. for 3 minutes to 10 hours. After that, it is water-cooled or air-cooled to 800 ° C. or less, subjected to high-temperature rolling at a temperature of 500 ° C. to 800 ° C. with a total processing rate of 40% to 90%, and then subjected to water quenching to remove oxide scale. Sharpened. Thereafter, cold rolling at a processing rate of 80% to 99.8%, intermediate solution heat treatment at 700 to 1020 ° C. for 5 seconds to 1 hour, aging precipitation heat treatment at 400 to 700 ° C. for 5 minutes to 10 hours, processing rate Finishing cold rolling of 3 to 25% and temper annealing at 200 to 600 ° C. for 5 seconds to 10 hours were performed to obtain a base material. Table 1 shows the compositions and properties of these test materials together with the inventive examples and comparative examples. After each heat treatment and rolling, acid cleaning and surface polishing were performed according to the state of oxidation and roughness of the material surface, and correction with a tension leveler was performed according to the shape.
In Comparative Examples 1-1, 1-2, 2-1, and 2-2 in Tables 1 and 2, high temperature rolling in the above process is performed at a temperature higher than 900 ° C., and an intermediate solution heat treatment is performed at 700. It was produced by performing cold rolling at a processing rate of less than 30 ° C. and a processing rate of greater than 30%. In addition, Comparative Examples 1-3, 1-4, 2-3, and 2-4 in Tables 1 and 2 were manufactured by performing high-temperature rolling in the above steps at a temperature higher than 900 ° C.

[Pretreatment of plating]
Next, as a pretreatment for plating, electrolytic degreasing and pickling were performed in this order. The conditions for electrolytic degreasing were as follows: the degreasing solution was NaOH 60 g / liter, the degreasing solution temperature was 60 ° C., the current density was 2.5 A / dm ² , and the degreasing time was 60 seconds.

The conditions of the pickling treatment in the pretreatment of the present example are as follows: an aqueous solution containing H ₂ O ₂ 35 ml / liter, H ₂ SO ₄ 61 ml / liter, and 1-propanol 10 ml / liter as condition a. It was used as a pickling solution and immersed in a pickling solution at 25 ° C. for 20 seconds. This condition is a pickling condition that can remove the work-affected layer formed on the surface layer. Using this condition a, pickling treatment of the samples shown in Table 1 was performed.

[Plating]
Next, as shown in Table 1, the base layer 1 is plated. Plating conditions of the underlying layer 1, for example in the case of nickel plating, plating solution _{Ni (NH 2 SO 3) 2} · 4H 2 O 500 g / _liter, the H 3 BO ₃ 30 g / l, NiCl ₂ · 6H _An aqueous solution containing ₂ O of 30 g / liter was used, the plating solution temperature was 55 ° C., and the current density was 10 A / dm ² . The same was done for cobalt plating. The plating thickness was appropriately adjusted with a coating thickness of 0.5 to 1 μm. In addition, when the base layer was formed from nickel and cobalt, each coating thickness was adjusted suitably and it adjusted so that the total thickness might be set to 0.5-1 micrometer.

Next, Cu plating is applied as the intermediate layer 2. The plating condition for the intermediate layer 2 is that the plating solution is an aqueous solution containing 250 g / liter of CuSO ₄ .5H ₂ O, 50 g / liter of H ₂ SO ₄ , and 0.1 g / liter of NaCl, respectively, and the plating solution temperature 40 ° C., and the current density 6A / dm ^2.

Further, tin plating is applied as the outermost layer 3. The plating conditions for the outermost layer 3 were an aqueous solution containing 80 g / liter of SnSO ₄ and 80 g / liter of H ₂ SO ₄ , a plating solution temperature of 25 ° C., and a current density of 2 A / dm ² .
The total layer thickness of the intermediate layer 2 and the outermost layer 3 was adjusted to be 0.2 to 10 μm.

[Reflow processing]
Finally, a reflow process was performed and a melting process was performed. The conditions for the reflow treatment are 300 ° C. and 60 seconds, but a desired plating configuration was obtained by adjusting as appropriate. By this reflow process, an alloy layer 4 is formed between the intermediate layer 2 and the outermost layer 3.

  A sample material was obtained by the above-described manufacturing steps of substrate production, plating pretreatment, plating, and reflow treatment.

The following property investigation was conducted on this specimen. Here, the thickness of the test material was 0.15 mm.
a. Area ratio [cube azimuth] of region where deviation angle from cube azimuth is within 20 °:
It was measured from the surface of the base material before plating. The measurement was performed by the EBSD method under the conditions of a measurement area of 500 μm ² and a scan step of 0.5 μm. The measurement area was adjusted based on the inclusion of 200 or more crystal grains.
b. Plating Configuration The cross section was mechanically polished, and the constituent elements of the underlayer 1, the intermediate layer 2, the alloy layer 4 and the outermost layer 3 were measured by EPMA measurement. In the case where the intermediate layer 2 and the outermost layer 3 did not remain due to the formation of the alloy layer 4, “disappearance” was indicated in the table.
c. Contact resistance after bending and heating:
A tin-plated material cut to a width of 10 mm and a length of 35 mm perpendicular to the rolling direction, and W-bended so that the bending axis is perpendicular to the rolling direction is GW (Good Way), so that it is parallel to the rolling direction. BW (Bad Way) was used as a W-bend, and 90 ° W-bend was performed. The bending angle of each bending part was 90 °, and the inner radius of the corner bending part was 0.15 mm.
Thereafter, it was heated to the atmosphere at a temperature of 140 ° C. for 120 hours.
Thereafter, the contact resistance at the apex of the bent portion was measured. For the measurement, an average value of an Ag probe, a load of 490 mN, and n = 10 was calculated using a four-terminal method. If the contact resistance value is 10 mΩ or less, it is judged as “good” and “○” is marked on the table, and if it exceeds 10 mΩ, it is judged as “No” and marked with “x” on the table. Evaluation was shown.
d. 0.2% yield strength [YS]:
Three test pieces of JIS Z2201-13B cut out from the rolling parallel direction were measured according to JIS Z2241, and the average value was shown.
e. Conductivity [EC]:
The specific resistance was measured by a four-terminal method in a thermostat kept at 20 ° C. (± 0.5 ° C.) to calculate the conductivity. The distance between the terminals was 100 nm.
f. Stress relaxation rate [SR]:
Measured according to the Japan Copper and Brass Association Technical Standard “JCBA T309: 2001 (provisional)”. FIG. 2 is an explanatory view of a stress relaxation test method using a downward deflection type cantilever type deflection displacement load test jig. In this test method, first, a test piece 11 is attached to a test jig (test apparatus) 12, given displacement is given at room temperature, unloaded after being held for 30 seconds, and the bottom surface of the test jig 12 is used as a reference surface 13, and this surface 13 and the distance between the specimen 11 deflection load point is measured as H _i. Next, the test jig 12 is held for a predetermined time (in this case, a constant temperature bath at 150 ° C. for 1000 hours), and then the test jig 12 is taken out from the thermostatic chamber to room temperature, and the flexible load bolt 14 is loosened and unloaded. After cooling the specimens 11 to room temperature, to measure the distance H _t of the deflection load point of the reference plane 13 and the specimen 11. After the measurement, the deflection displacement is given again. In FIG. 2, 11 represents a test piece at the time of unloading, and 15 represents a test piece at the time of bending load. Obtaining a permanent deflection displacement [delta] _t by the following equation.
δ _t = _H i -H _t
From this relationship, the stress relaxation rate (%) is calculated as δ _t / δ ₀ × 100.
Δ ₀ is the initial deflection displacement of the test piece necessary to obtain a predetermined stress, and is calculated by the following equation.
δ ₀ = σl _s ² /1.5Eh
Here, σ: surface maximum stress (N / mm ² ) of the test piece; h: plate thickness (mm), E: deflection coefficient (N / mm ² ), l _S : span length (mm).

  Regarding the characteristics of the base material, those having characteristics of 0.2% proof stress (YS) of 500 MPa or more, conductivity (EC) of 30% IACS or more, and stress relaxation rate (SR) of 30% or less are good characteristics. It is assumed that this is a copper alloy material.

  As shown in Table 1, Inventive Example 1-1 to Inventive Example 1-16 were excellent in all of proof stress, conductivity, stress relaxation resistance, bending resistance and contact resistance after heating. However, when the provisions of the present invention were not satisfied, the characteristics were inferior. That is, in Comparative Examples 1-1 to 1-4, since the cube azimuth area ratio of the substrate was low, cracks occurred in the plating during bending, and the contact resistance after heating increased.

(Example 2)
Using the elements shown in Table 2 and a copper alloy consisting of Cu and inevitable impurities in the remainder, the substrate was manufactured by the same manufacturing method as that described in Example 1, and the treatment before plating was performed. In addition, the condition of the pickling treatment in the pretreatment at this time was as a condition b, in which an aqueous solution containing 61 ml / liter of sulfuric acid was used as a pickling solution and immersed in a pickling solution at 25 ° C. for 30 seconds. This condition is only an action of removing the oxide film formed on the surface layer, and is a condition that does not lead to removal of the work-affected layer. Using this condition b, the pickling treatment of the samples in Table 2 was performed.
For the plating, the intermediate layer 2 and the outermost layer 3 were plated without performing the plating of the underlayer 1, and the reflow treatment was performed. By this reflow process, an alloy layer 4 was formed between the intermediate layer 2 and the outermost layer 3. Each plating condition was performed by the method described in Example 1.
Invention Example 2-16 and Comparative Example 2-1 to Comparative Example 2-4 were obtained from Invention Example 2-1, and a characteristic investigation was performed by the same measurement method as that described in Example 1. The results are shown in Table 2.

  As shown in Table 2, Inventive Example 2-1 to Inventive Example 2-16 were excellent in all of yield resistance, electrical conductivity, stress relaxation resistance, bending resistance and contact resistance after heating. However, when the provisions of the present invention were not satisfied, the characteristics were inferior. That is, in Comparative Examples 2-1 to 2-4, since the cube azimuth area ratio of the substrate was low, cracks occurred in the plating during bending, and the contact resistance after heating increased. From the results of these examples, it can be seen that setting the cube orientation area ratio within a predetermined range affects the characteristics rather than whether or not the work-affected layer is removed. For this reason, since it turns out that the outstanding effect which cannot be obtained only by removal of a work-affected layer is obtained in this invention, it turns out that the outstanding effect which is not in a prior art is acquired.

11 Test piece (unloading)
12 Test Jig 13 Reference Surface 14 Deflection Load Bolt 15 Test Piece (When Deflection Load)

Claims (8)

On a base made of a copper alloy,
At least an alloy layer containing copper and tin, a copper alloy material for electric and electronic parts which is formed by heating and melting treatment and plating treatment,
The area ratio of the region within 20 ° from the cube orientation {0 0 1} <1 0 0> in the EBSD method crystal orientation measurement of the substrate is 5% or more,
The substrate contains at least one of nickel or cobalt in a total amount of 0.4 to 5.0 mass%, contains silicon in an amount of 0.1 to 1.5 mass%, and the balance is composed of copper and inevitable impurities, The substrate is obtained by removing a work-affected layer on the surface layer,
Adjacent on the substrate, which undercoat plating layer is provided containing at least one of nickel or cobalt,
The copper alloy material was bent at 90 ° W with an inner radius of 0.15 mm, and the contact resistance at the apex of the bent portion after heating in the atmosphere at a temperature of 140 ° C. for 120 hours had a load of 490 mN via an Ag probe. A copper alloy material for electrical and electronic parts, characterized by being 10 mΩ or less under the conditions of On a base made of a copper alloy,
At least an alloy layer containing copper and tin, a copper alloy material for electric and electronic parts which is formed by heating and melting treatment and plating treatment,
The area ratio of the region within 20 ° from the cube orientation {0 0 1} <1 0 0> in the EBSD method crystal orientation measurement of the substrate is 5% or more,
The base body contains at least one of nickel and cobalt in a total amount of 0.4 to 5.0 mass%, silicon in a range of 0.1 to 1.5 mass%, tin, zinc, silver, manganese, boron, phosphorus, magnesium. , Chromium, iron, titanium, zirconium and hafnium at least one selected from the group consisting of 0.005 to 2.0 mass% in total, with the balance being composed of copper and unavoidable impurities, the substrate being a surface layer Removing the damaged layer of
Adjacent on the substrate, which undercoat plating layer is provided containing at least one of nickel or cobalt,
The copper alloy material was bent at 90 ° W with an inner radius of 0.15 mm, and the contact resistance at the apex of the bent portion after heating in the atmosphere at a temperature of 140 ° C. for 120 hours had a load of 490 mN via an Ag probe. A copper alloy material for electrical and electronic parts, characterized by being 10 mΩ or less under the conditions of   The copper alloy material for electrical and electronic parts according to claim 1 or 2, wherein an outermost layer made of tin or a tin alloy is provided on the alloy layer.   The copper alloy material for electric and electronic parts according to claim 1, wherein an intermediate layer made of copper or a copper alloy is provided between the base plating layer and the alloy layer.   An intermediate layer made of copper or a copper alloy is provided between the base plating layer and the alloy layer, and an outermost layer made of tin or a tin alloy is provided on the alloy layer. The copper alloy material for electrical and electronic parts according to claim 1 or 2.   An electrical / electronic component obtained by processing the copper alloy material according to any one of claims 1 to 5. Containing at least one of nickel or cobalt in a total amount of 0.4 to 5.0 mass%, containing silicon in a range of 0.1 to 1.5 mass%, the balance being a copper alloy having a composition consisting of copper and inevitable impurities, and homogeneous On the substrate obtained by hot rolling the heat-treated ingot at 850 to 1020 ° C., water-cooling or air-cooling to 800 ° C. or less, and performing high-temperature rolling at a total processing rate of 40% or more at 500 to 800 ° C.,
A base plating layer containing at least one of nickel or cobalt, a copper plating layer made of copper or a copper alloy, and a tin plating layer made of tin or a tin alloy are formed in this order. A method for producing a copper alloy material for electrical and electronic parts, wherein the tin plating layer is melted by a heat melting treatment for 120 seconds to form an alloy layer composed of constituent elements of the copper plating layer and constituent elements of the tin plating layer. There,
The area ratio of the region within 20 ° from the cube orientation {0 0 1} <1 0 0> in the EBSD method crystal orientation measurement of the substrate after the heat-melting treatment is 5% or more, A method for producing a copper alloy material for electronic parts. Contains at least one of nickel or cobalt in a total amount of 0.4 to 5.0 mass%, contains silicon in a range of 0.1 to 1.5 mass%, tin, zinc, silver, manganese, boron, phosphorus, magnesium, chromium, iron , A copper alloy containing at least one selected from the group consisting of titanium, zirconium and hafnium in a total amount of 0.005 to 2.0 mass%, with the balance being composed of copper and inevitable impurities, and subjected to homogenization heat treatment On the substrate obtained by hot rolling the lump at 850 to 1020 ° C., water-cooling or air-cooling to 800 ° C. or less, and performing high-temperature rolling at a total processing rate of 40% or more at 500 to 800 ° C.,
A base plating layer containing at least one of nickel or cobalt, a copper plating layer made of copper or a copper alloy, and a tin plating layer made of tin or a tin alloy are formed in this order. A method for producing a copper alloy material for electrical and electronic parts, wherein the tin plating layer is melted by a heat melting treatment for 120 seconds to form an alloy layer composed of constituent elements of the copper plating layer and constituent elements of the tin plating layer. There,
The area ratio of the region within 20 ° from the cube orientation {0 0 1} <1 0 0> in the EBSD method crystal orientation measurement of the substrate after the heat-melting treatment is 5% or more, A method for producing a copper alloy material for electronic parts.

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